Force Firefox extensions to work in the latest version

When Firefox updates to a new version, some extensions are disabled. However, you can easily edit the extensions to make Firefox re-enable them -- no particular expertise required.

Extension authors sometimes abandon their creations, and when Firefox enters a new version, it will refuse to use extensions that are not tagged as compatible.

Basically, the extension installer is just a zip archive. The installation information file inside contains a "maxversion" note to Firefox letting it know what versions the extension is appropriate for. Just change this value and you're good to go!

Warning! The extension may not be installable for a reason. If you break Firefox, close it and start it in safe mode, then remove the extension.

Horrendously over-explicit instructions:

  1. Save the install file to the desktop. (Right-click, "Save Link As...")
  2. Rename the file's extension from .xpi to .zip. (In Windows, go to a folder window and click Tools -> Folder Options, then unhide extensions.)
  3. Open the file. (WinZip or some other archive program.)
  4. Extract the install.rdf file to the desktop. (Drag it.)
  5. Open the file in a plain-text editor (Notepad, vi, Gedit, etc.)
  6. Find a block that starts with <em:targetApplication>. If there is more than one, choose the one that contains the string {ec8030f7-c20a-464f-9b0e-13a3a9e97384}, the ID of Firefox.
  7. Find the line that starts with <em:maxVersion>. You will see a value that looks something like 1.5.0.* -- a version number.
  8. Change that value to the current version of Firefox.
  9. Pack everything back up! Save the install.rdf file, pull it back into the archive, rewriting the old version. Rename the extension's file extension from .zip back to .xpi.
  10. Install the edited extension in Firefox by dragging it onto a Firefox window. Complete the installation by restarting Firefox.
As Firefox grows and changes, extensions can no longer rely on being able to interact with it the same way. To prevent crashes and other bugs, the extensions' authors test them out with different versions of Firefox, then make note of the highest version the extension was compatible with. When you try to install an extension, Firefox first checks the extension's self-proclaimed max-version for compatibility. Of course, if the author hasn't worked with the extension in a while, the max-version field can be out of date. You can change it yourself, but at your own risk.

Responses: One so far

  1. Atomic says:

    another method is a combination of downthem all and 7zip
    put the link location in downthem all and then just down load it to somewhere on your computer
    open it in 7zip file manager and modify it that way